Prep the Chiles and Vegetables

1. Remove stems and shake out most seeds from the dried chiles.
2. Toast the chiles in a dry skillet for 20 to 30 seconds per side.
3. Soak the toasted chiles in hot water for 15 to 20 minutes until softened.
4. Roast onion, tomatoes, and garlic until charred.

Blend the Sauce

1. Drain and add the chiles to a blender with the roasted vegetables, spices, some stock, and salt.
2. Blend until very smooth, adding more liquid if necessary.
3. Strain the sauce through a fine mesh strainer into a bowl.

Cook the Birria

1. Season beef chunks with salt and pepper.
2. Sear the beef in a hot pan for a few minutes to brown.
3. Add beef to the slow cooker.
4. Pour the birria sauce over the beef.
5. Add beef stock until the meat is mostly covered.
6. Toss in bay leaves.
7. Cook on low for 8 to 9 hours or high for 5 to 6 hours.

Finish the Consommé

1. Shred the beef with two forks and return it to the slow cooker.
2. Skim off excess fat from the top of the broth.
3. Taste the consommé and adjust flavors with salt, vinegar, or stock.